The present invention relates to a fuel cell separator, fuel cell device, and electronic applied device, and more particularly to a fuel cell separator, fuel cell device, and electronic applied device wherein the fuel cell device can be reduced in size with almost no limitation to layout of a fuel cell body in the fuel cell device, and air can be smoothly supplied to each generating cell.
A fuel cell is a power generating device including a generating cell for performing electric power generation by the electrochemical reaction of a fluid fuel such as hydrogen gas or methanol and a fluid oxidant such as oxygen contained in air. In the case of a solid polymer type fuel cell, it generally has a structure formed by sandwiching a proton conductor membrane between an oxygen electrode and a fuel electrode. The oxygen electrode is supplied with air containing oxygen, and the fuel electrode is supplied with a fluid fuel. In performing electric power generation in the solid polymer type fuel cell, ions (protons) move in an electrolyte membrane as an ion exchange membrane to react with the oxygen supplied from the oxygen electrode, thereby generating a current, whereas producing water on the oxygen electrode. Such a generating element of the fuel cell is referred to as an MEA (Membrane and Electrode Assembly). By arranging a plurality of MEAs in a plane or arranging a plurality of generating cells each formed by sandwiching an MEA between a pair of separators in a plane, a fuel cell having a planar structure is configured. Alternatively, by stacking a plurality of MEAs or a plurality of generating cells, a fuel cell having a stack structure is configured.
Further, since the product obtained by the electric power generation in the fuel cell is water, the fuel cell has received attention in recent years as a power generating element causing no environmental pollution, and it has recently been tried to use the fuel cell as a driving power source for driving an electric vehicle or a hybrid vehicle in the field of transport vehicles.
Thus, the use of the fuel cell as a driving power source for transport vehicles is greatly expected. Further, the practical use of the fuel cell in a home power supply system is also expected, and various applications of the fuel cell are examined on a small-sized power source or portable electronic equipment such as a notebook personal computer, mobile phone, and PDA (Personal Digital Assistant), utilizing a weight reduction and size reduction of the fuel cell. In such a fuel cell, it is important to stably output a required electric power and to reduce the size to a portable size. Under these circumstances, various technical developments are being made actively.
Of the pair of separators constituting the generating cell, the separator touching the oxygen electrode of the generating element is formed with a fluid oxidant supply channel for supplying a fluid oxidant such as oxygen to the oxygen electrode. The fluid oxidant supply channel has an opening exposed to an end surface of the separator for taking the outside air into the channel to supply it to the oxygen electrode. The fluid oxidant supply channel is formed as a groove extending in the longitudinal direction of the separator so as to be exposed to the opposite ends of the separator. The outside air supplied from one of the openings of the channel is made to flow in the channel, and then discharged from the other opening to the outside of the generating cell. A plurality of fluid oxidant supply channels may be arrayed in the transverse direction of the separator, so as to efficiently supply oxygen to almost all the surface of the oxygen electrode. An air supplying fan is provided along a side surface of the generating cell to collectively supply air to all the fluid oxidant supply channels. For example, in the case that the fuel cell body has a stack structure formed by stacking a plurality of generating cells to generate a required electric power, the air supplying fan is provided separately from the fuel cell body to collectively supply air to all the fluid oxidant supply channels.
However, in the above case that the air supplying fan is provided separately from the fuel cell body, the layout of the fuel cell body is limited by the layout of the air supplying fan. Moreover, since the air supplying fan is provided in a fuel cell device, a size reduction of the fuel cell device itself is difficult.
Further, in the case of dispersively arranging a plurality of fuel cell bodies in electronic equipment to drive various elements mounted in this electronic equipment at required positions, the air supplying fan provided separately from each fuel cell body causes the production of a waste space in the electronic equipment, resulting in the hindrance to size reduction of the electronic equipment to be driven by the electric power generated in each fuel cell body.
Furthermore, there are variations in amount of air to be supplied by the air supplying fan between a central portion and an outer circumferential portion thereof. As a result, there are variations in amount of air to be supplied into the fluid oxidant supply channels between the channels exposed to the central portion of the fan and the channels exposed to the outer circumferential portion of the fan, causing a possibility that the electric power generation by the fuel cell body may become unstable. Particularly, if there are variations in air supply amount among the generating cells forming a stack structure, there is a possibility that the power generation efficiency in a specific one of the generating cells may be lowered.